diff -r 087008dfb005 xen/arch/x86/traps.c
--- a/xen/arch/x86/traps.c	Mon Sep 15 17:10:43 2008 +0100
+++ b/xen/arch/x86/traps.c	Tue Sep 16 13:57:31 2008 +0200
@@ -2242,6 +2242,12 @@ static int emulate_privileged_op(struct 
             if ( rdmsr_safe(regs->ecx, regs->eax, regs->edx) )
                 goto fail;
             break;
+        case MSR_AMD_PATCHLEVEL:
+            if ( boot_cpu_data.x86_vendor != X86_VENDOR_AMD )
+                goto fail;
+            if ( rdmsr_safe(regs->ecx, regs->eax, regs->edx) )
+                goto fail;
+            break;
         default:
             if ( rdmsr_hypervisor_regs(regs->ecx, &l, &h) )
             {